1. pierce or make hole(s) in.   Hint First letter clue   2. make valid or confirm.   First letter clue   3. mean or insinuate.   First letter clue   4. echo or reflect sound, light or heat.   First letter clue   5. exhaust vigor of or undermine.   First letter clue   6. introduce or originate.   First letter clue   7. release special substance or hide away.   First letter clue